Genetic analysis of flowering and physiological maturity characteristics by generation mean analysis of four hybrids of maize: growth criteria

الملخص EN

In order to find out the relative amount of the components of genetic variance and forms of epistasis interactions using the generation mean analysis method for maize hybrids vary by the date of flowering and maturity.

a field experiment was carried out at the field crops research station, college of agricultural engineering sciences-university of Baghdad-al-Jadiriyah to estimate the components of genetic action, genetic influences the non allelic effects and its interactions that control the inheritance of the growth criteria traits of the selected inbred lines and their resulting hybrids using the generation mean analysis.

five pure inbred lines maize (ZA17WR, ZI17WZ, ZM74, ZM19 and ZM49W3E) were selected from fifteen different inbred lines with flowering and maturity dates.

in the spring season 2019 and were cross-bred according to the target (late × late) (late × early) (early × late) and (early × early) in the second fall season (2019).it was entered into a backcross crossing program to analyze the average generations in the spring season (2020) to produce the (six generations) which are P1, P2, F1, F2, Bc1 and Bc2.

the six generations (P1, P2, F1, F2, Bc1 and Bc2) for the four hybrids were evaluated in comparative experiments using a randomized complete block design (RCBD) with three replicates.

in the fall season 2020.

genetic analysis was done for scaling and analysis for the six criteria, according to Mather and Jenks (1982) for the traits of the number of days to silking, days to physiological maturity, crop growth rate and yield of area unit (ton.

hector).

the results showed significant differences between the six generations, as the first generation came early by reaching silking and physiological maturity.

it also excelled by giving it the highest rate, crop growth rate and yield area unit.

the four hybrids had a hybrid vigor and hetrosis negative in the desired direction towards early silking, and a positive hybrid vigor for the two traits of the crop growth rate and yield in the desired direction towards their increment.

the results of the genetic analysis of scaling analysis showed the significant difference of the four criteria a, b, c, d according to the trait and the difference of the hybrids.

this was reflected on the dominance and additive influences beside their epistasis interactions.

the first, third and fourth hybrids showed a dominance action of silking trait and the type of interaction was duplicated epistasis, and in the second hybrid, the hybrid showed a dominance action and the complementary type of epistasis interaction for the similarity of the reference to the dominance genetic action with the non-allelic interaction (dominance x dominance).

as for the traits of physiological maturity, it gave a dominance effect in the four hybrids, and the type of epistasis differed.

it was duplicate in the first, second and third hybrid, and complemented by the fourth hybrid.

while there was no significant effect of both the dominance and additive effects in the first and second hybrids for the crop growth rate, the third and fourth hybrids showed a dominance effect and the type of complementary epistasis.

second.

from all above, we conclude that the additive and non-additive genetic action controls the inheritance of yield, flowering, physiological maturity and the crop growth rate, therefore we recommend using the method of reciprocal recurrent selection (RRS).